Stoppers for receptacles having screw-threaded necks



United States Patent OfiFice 3,372,833 Patented Mar. 12, 1968 3,372,833 STQPPERS FOR RECEPTACLES HAVENG StIREW-THREADED NECKS Daniel Baranne, 3 Ave. de la Prineesse Mathilde, 95 Saint-Gratien, Seine-et-Oise, France Filed Dec. 3, 1965, Ser. No. 511,891 Claims priority, application France, Aug. 4, 1965,

,218' 3 Claims. (Cl. 226-39) ABSTRACT OF THE DISCLOSURE The present stopper is for attachment to containers having a neck with external threads and which stopper when assembled to said neck cannot be readily detached therefrom. The stopper includes a tubular body insertable in the container neck, a hollow plug member insertable in said tubular body, an internally threaded cap for threaded engagement with said neck and having a central opening in which the top of said plug member mates and having a skirt and annular rib for cooperating with said inner plug and tubular body to provide three points of lateral sealing around said inner plug to prevent the undesired escape of material from said container other than through said cap center opening.

This invention relates to a captive stopper assembly for tubes or any containers provided with a screw neck, and more particularly for tubes adapted to be flattened, as disclosed in my prior U.S. Patent No. 3,305,127 of Feb. 21, 1967.

The known stopper assembly disclosed in the above patent application comprises essentially a tubular body partly engaging the tube neck, an inner tubular or plug member formed with lateral apertures and partly engaging the inner space of the body so as to expand inner projections thereof within the tube and beneath said neck for locking said body in said tube, and finally a cap formed with an upper central hole which is screwed on the neck of the container to enclose the resulting assembly.

In the closed position obtained by screwing the cap, the upper bottom wall thereof engages the outer end of the tubular body and its central hole is closed by said plug member.

In the open position, the product kept in the container may escape therefrom through the plug member apertures and through the central hole of the cap, the complete removal of this cap being prevented by a circular shoulder or bead formed at the bottom of the cap and movable circularly about the neck of the container in a recess or groove formed to this end beneath the screw-threaded portion of said neck.

The three elements constituting the tubular body, the

plug member and the cap are advantageously made of relatively flexible or elastic plastic materials.

The stopper thus constituted and assembled as set forth in the above referred US. Patent No. 3,305,127 operates quite satisfactorily, but when it is desired to impart a massive appearance to the stopper the manufacture of this stopper may involve the use of relatively excessive thicknesses in the cap, complications in the moulding equipment for obtaining the retaining bead and the necessity of adhering to very close tolerance in the machining of the neck of the container which must be very closely adapted to the bead dimensions.

It is the essential object of the present invention to avoid these inconveniences by providing novel features of the cap structure adapted to corresponding structures of the neck of the container, of the tubular body and of the internal plug member. The desired results are obtained by resorting to a combination of these novel features but it Will be readily understood by anybody conversant with the art that part of these results could be obtained by applying only one fraction of the features contemplated in the present improvements and set forth hereinafter, without departing from the spirit and scope of the invention.

A first feature characterizing this invention consists in providing said annular bead projecting within the cap above the tapped portion of the cap instead of at the bottom thereof, thus permitting the movement of this head about the tubular body portion externally of the container, beneath an upper peripheral flange of said tubular body, whereby the operation of the device, from which the captive characteristic is derived, is no more dependent on the accurate machining of a groove on the neck of the container.

Whereas the end seal or fluid-tight joint is provided in the closed position by the relative engagement of the cap and the plug member engaging the central hole of the cap, the lateral seal is advantageously provided, within an open tubular extension of said plug member, by an inner skirt depending from the top of the cap.

Finally, the axial movement of the cap in the closing direction is advantageously limited by a cylindrical collar depending from the top of said cap and fitting around the tubular extension of said inner plug member while partaking in the lateral fluidtightness of the device by abutting in its innermost position against the upper edge of said tubular body.

In order to alford a clearer understanding of the novel features proposed herein, a typical form of embodiment of a captive screw stopper assembly having the features broadly set forth hereinabo ve will now be described by way of example with reference to the attached drawing of which the single figure is an axial section showing the stopper assembly in its closed position.

In the drawing, the reference numeral 31 designates the upper end of a tube adapted to be flattened and to be provided with the captive plug assembly of this invention. To this end, the tube comprises a screw-threaded neck 32 in which the tubular body 33 is engaged, this body 33 carrying at its lower end lugs 34 adapted to expand beneath the outflared or tapered portion 31 at the bottom of neck 32 when the hollow plug member 35 is inserted into the tubular body 33 according to the assembly method disclosed in the Patent No. 3,305,127.

Above the neck, the tubular body 33 comprises a shoulder 36 engageable by an outer flange 37 of said plug member, an open-top tubular extension or cylindrical collar 38 extending upwards from said flange. This flange 37 projects slightly outwards from the outer peripheral wall of said collar 38 and is retained within the tubular body 33 by resiliently engaging the lower edge of an inner projection 39 which may be either continuous or divided into several fractions or sectors, formed on the inner face of an upper widened portion 48 of said tubular body 33.

The upper edge of the tubular body 33 is formed with an outer abutmenvforming peripheral head 43 adapted to retain the cap as will be explained presently.

To complete the description of the plug member, it may be noted that its upper central portion 42 located Within the tubular extension or collar 38 is closed at the top by a bottom wall 43 and formed with lateral outlet apertures 44 opening into the surrounding annular chamber provided between this central portion 42 and the open-top tubular extension or collar 38.

The closing cap is moulded from suitable plastic material (like the tubular body and the plug member) to have an adequate elasticity and comprises a top 45 formed with a central aperture 46 adapted to engage in a fluid-tight manner the outer wall of the upper portion 42 of said plug member. It further comprises a peripheral lateral wall 4'7 depending from the outer periphery of said top 45, and a widened base portion 48 formed with inner screw threads along a certain portion 49 of its height which is inferior to the total height of the screw-threaded portion of the neck of the container.

Depending from the top wall 45 of the cap is an inner skirt 50 adapted to slide within the tubular extension or collar 38 and form a leak-proof joint therewith. Between the skirt 50 and the lateral wall 47 an annuiar rib 51 is also provided on the inner face of cap 45 and adapted to the end of the screwing movement to engage the upper edge of the tubular body to limit the cap movement during the screwing thereof for closing the tube.

Just above the tapped portion, the inner surface of the cap comprises an annular retaining bead 52 moulded integrally with the cap and adapted to move around the upper portion 40 of the tubular body beneath the peripheral bead 41 retaining its companion bead 52 and therefore the cap upon completion of the permissible unscrewing or cap opening movement.

The permissible axial stroke of bead 52 between its lowermost position shown in the drawing and its uppermost position in which it abuts against its companion abutment-forming bead 4-1 is advantageously slightly inferior to the height of the tapped portion of the cap which overlies the bead 52 in order to afford a certain axial compression of the tapped portion at the end of the unscrewing movement, thus ensuring the automatic return of the tapped portion 49 of the cap to the position of proper relative engagement with the neck 32 when screwing in the cap for reclosing the tube, without requiring the application of any axial thrust on this cap.

In the fully closed position shown in the drawing the cap has been screwed home until its annular rib 51 engages the upper edge of the tubular body, the tapped portion 49 of the cap having engaged one fraction of the height of the screw-threaded portion of neck 32 downwards. The height of this screw-threaded portion is slightly greater than that of said tapped portion, thus affording a suth'cient tolerance in machining the tube neck.

In this position, the central hole of the cap will be in fluid-tight engagement with the outer surface of the upper closed portion of the central portion 42 of the plug member; and the inner skirt 50 fits in fluid-tight engagement into the open-top tubular extension or collar 38 of this plug member, besides, this plug member itself is fitted between the skirt 50 and the annular rib 51. This arrangement and relative positioning of parts will assist in keeping the tubular extension of collar 38, the skirt and the closed top portion 42 of the plug member in a state of radial compression, thus improving the fluidtightness of the assembly.

When it is desired to use the content of the tube it is only necessary to unscrew the cap which is thus moved axially away from the tube body, the tubular body and the plug member, whereby an annular outlet passage is formed about the portion 42 of the plug member and at the central hole 46 of the cap which has been freed from the plug member. Shortly before the cap unscrewing movement is completed the retaining head 52 is stopped by the annular abutment 41 of the tubular body and since the permissible axial stroke of this head is slightly shorter than the height of the tapped portion 4?, completing the unscrewing movement will apply a vertical compressive force to the tapped portion 49 until it escapes from the screw-threaded portion of neck 32 and is subjected to a kind of prestress whereby it will automatically re-engage the screw-threaded portion when the cap is re-screwed.

It is clear that when assembling the plug components the bead 52 will easily clear the annular abutment 41, this movement being facilitated if desired by providing properly bevelled edges such as bevel 53 on the top of abutment 41 and a corresponding bevel 54 on the lower edge of head 52. Besides, the engagement of tubular extension 3% into the annular rib 51 may be facilitated by a bevelled edge 55 at the root of this rib 51.

What I claim is:

1. A stopper for a receptacle provided with an externally screw-threaded neck, comprising a tubular body of a resilient synthetic plastic material having an enlarged upper portion capable of being seated on the end of said neck with an outwardly extending peripheral bead at the end thereof and a cylindrical skirt depending from said upper portion and capable of extending into said neck, said skirt having bottom lugs projecting in wardly for being mounted within said receptacle below said neck, an inner hollow plug member of a resilient synthetic plastic material which is closed at its top, has lateral openings below said top and a tubular collar surrounding and radially spaced from, the upper portion of said hollow plug member, said inner hollow plug member extending within said skirt of the tubular body and expanding outwardly the bottom of said skirt provided with said lugs, an internally screw-threaded cap of a resilient synthetic plastic material capable of being screwed on said neck and provided at its upper end with a top having a central hole for receiving the closed top of said inner hollow plug member when said cap is fully screwed on the neck, the internal surface of said cap top having an inner skirt extending against and in fluid-tight engagement with said tubular collar of the hollow plug member, said cap having an internal annular rib slideably engaging said tubular collar on the opposite side thereof to said cap inner skirt and adapted to engage the upper edge of said tubular body when the cap is fully screwed into a closed position and, said cap being provided above its inner tapped portion with an annular retaining bead.

2. A stopper as claimed in claim 1, wherein the outwardly extending peripheral bead of the tubular body is capable of cooperating with said annular retaining bead of the cap for retaining said cap on said tubular body at the end of the unscrewing operation of said cap.

3. A stopper as claimed in claim 1, in which the distance between said outwardly extending peripheral bead of said tubular body and the end of the neck on which the upper portion of said tubular body is hearing is slightly inferior to the height of the inner tapped portion of said cap, whereby at the end of the unscrewing operation said tapped portion released from the screw-threaded portion of the tube neck is subjected to a certain degree of axial stress adapted to automatically re-engage said tapped portion on said screw-threaded portion for re-closing the tube.

References Cited UNITED STATES PATENTS 3,032,240 5/1962 Dunklee 215-74 X 3,263,851 8/1966 Grimsley 21574 3,305,127 2/1967 Baranne 220-39 THERON E. CONDON, Primary Examiner.

G. T. HALL, Assistant Examiner, 

